Implantable infusion pumps for dispensing controlled volumes of a drug (e.g. insulin) have been proposed and even attempts at implementation and commercialization made.
One such pump is the MMT2001 Implantable Pump System as sold by Minimed Inc. of Northridge, Calif. This device presented the user with the ability to perform basic infusion actions such as the delivery of a basal rate, delivery of a temporary basal rate, or the delivery of a meal bolus. The user was, however, not presented with the ability to perform more sophisticated delivery related operations that may be desirable for optimum control of blood glucose level. When using this system three delivery options exist: (1) delivery of a standard but programmable basal rate, (2) delivery of a standard basal rate and a meal bolus simultaneously, or (3) delivery of a temporary basal rate either immediately or at a programmable start time within a specifiable start time. In this system not only could a meal bolus and a temporary basal rate not occur at the same time, they could not be programmed into the system when the other was already programmed but delivery not yet completed even though no overlap in delivery between the two amounts might exist. As such the user could only program one variable rate into the system at a time, even in the event that several variable rates may be desired to follow one another. As such, this system is less than optimal with regard to user convenience in programming his/her insulin treatment.
The system also suffered from an external controller that was large, hard to carry and awkward to use. The controller dimensions are 6.0 inches by 3.5 inches by 1.3 inches with a display that is a small fraction of the size of the face of the controller. The controller included a cover plate that would close over the display area when not in use and would be opened during use. More particularly, during programming the cover plate is opened at a ninety-degree angle relative to the front of the display to allow viewing of the display and to allow positioning of the cover plate immediately over the site of the infusion pump so that successful telemetry communication may occur. As such the system does not supply delivery or system status related information to the user accept at the times that the user elects to open and turn on his/her controller.
The system further suffers from the inability of the implantable device to send out unsolicited telemetry messages to the controller concerning operational conditions within the implantable device. As such, system conditions within the implantable device (other than communication related failures) are primarily conveyed to the user via an auditory alarm that is internal to the implantable device.
The system further suffers from the entire operational history of the pump being subject to loss as this historical data is only held in the controller.
The system further suffered from a relatively short life for the implantable device of approximately 2.5 years.
Based on the above noted shortcomings, and other shortcomings of systems in the field, a need exists for improved systems that offer enhanced programming capabilities, enhanced user interface capabilities, reduced controller size, enhanced operational performance, enhanced security of system/patient historical data, enhanced safety features, and/or enhanced implantable device life.
It is believed that related shortcoming may exist in other ambulatory medical devices as well, such as in externally carried infusion pumps, implantable pacemakers, implantable defibrillators, implantable neural stimulators, implantable physiological sensors, externally carried physiologic sensors, and the like.